True Templar

To achieve level 20 in Assassin's Creed: Revelations multiplayer you will need to gain around 137,000 experience points in ranked matchmaking.

While the amount of xp you gain will vary depending on how well you play the game most will gain around 1500 - 2000 xp per game. This means the average player will hit level 20 between 70 - 100 complete games.

Escort Mission is likely the best gametype to play in as it will allow to defending players xp not only for kills but for guarding your npc.